Dispenser of doses of liquids and paste-like masses

ABSTRACT

A dispenser for the metered discharge of liquids and in particular pasty masses, having a delivery pump actuatable by finger pressure. The pump has a vacuum-type action and a restoring spring and pressure and suction valves. The container to which the pump is to be attached preferably is a container having resilient walls. The pump has a discharge bore with a closure element, to open and close the discharge bore. The pump has a pump chamber that is open and closed at its top end by a pressure valve. The pressure valve is connected to a plunger. A suction valve is axially spaced from the pressure valve and the suction valve is positioned to open and close the bottom end of the pump chamber. Contact zones are provided between the suction valve and the pressure valve. The plunger is displaceable in the delivery direction, and a restoring spring is located outside of the pump chamber. The restoring spring is clamped between a shoulder surrounding the pump chamber and a plunger flange. A sliding guidance is connected with a metering head. The guidance has a circumferential edge that acts as a stop and there is a closure element movable in the discharge bore by a lever key connected thereto.

The invention relates to a liquid and paste dispenser and moreparticularly to a finger operated paste dispenser.

A paste dispenser of similar type is described for example in EP 0 230252 A2. In this case suction and pressure valves are formed as hingedflaps, of which the opening and closing function can be affected by thehinging and adhesive forces. Furthermore there are no measures cited, inorder to attain a tight closure of the discharge bore with gas emittingmedia.

It is an object of the invention to propose a paste dispenser of thegeneric type, which produces an intensive suction effect with simplemeans, in order to achieve a high filling degree of the pump room inconnection with mechanical aids, which additionally support the valvefunction and in order to guarantee emptying of a storage container,which can be changed by underpressure.

It is furthermore an object to open a closure, coupled with theactuating key, of the discharge bore before the start of delivery and toclose it after the end of delivery.

The advantages attainable by the invention consist in that a pastedispenser, which can be manufactured with simple means, can be manuallyoperated by finger pressure, and that measures for attaining a highsuction effect permit the combination for example with commercial tubesserving as storage containers, whereby the medium can be protectedagainst drying-in and gas losses by a controllable closure, and thatenvironmental pollution is fought by reusing the metering head.

In a further embodiment of the invention it is advantageous forattaining a high suction effect to have the dead space in the lowestplunger position tend toward zero, if possible, and on this occasion toproduce a contact zone between the pressure valve and the suction valve,in order to open the suction valve as soon as the suction lift startsnot only by underpressure, but also by adhesive forces, which arecreated in the contact zone by cooperation of the pasty mass. In likemanner the pressure valve meets an additional sealing force with thestart of the suction lift. Within the opening lift of the suction valve,which is defined by stop edges on guide segments, the suction valve islongitudinally moved together with the plunger, so that theunderpressure produced by the plunger is available in its full strengthfor taking in the paste and not only for elevating the suction valve.

A further embodiment of the invention shows that the contact zone fordriving the suction valve with the start of the suction lift is effectedby means of a plug cone, which adjoins the valve seat of the pressurevalve and to which a corresponding bore in the suction valve isassociated. The suction valve is opened by the positive locking of theplug cone connected with the suction valve, as soon as the suction liftof the plunger starts. Simultaneously, the closing pressure of thepressure valve is increased to the same extend.

A further embodiment of the contact zone between the pressure and thesuction valve shows a friction bar fixedly connected with the pressurevalve, which penetrates a bore of the suction valve, the fit being suchthat closeness as well as friction are produced. In this connection, theopening and closing movements of the suction and pressure valve aresupported during both the suction and the delivery lift.

A further embodiment of the pressure valve consists in that forattaining an untilted longitudinal guide, guide webs are molded on theconical pressure valve seat, and that with an embodiment in a plasticmaterial a spring bar is molded on, the lateral swinging-out movement ofwhich produces the spring potential, which supports the closeness of thepressure valve during the suction lift.

As far as the subject matter of the invention is provided for media,which require a special closure of the discharge bore because ofdrying-in or gas emissions, then a lever key is provided for thispurpose, which in simple manner has a double function, and which on theone hand brings the closure element into its open position when beingactuated, and on the other hand, when a stop on the metering head isreached, effects the latter's actuation. It is advantageous with thisarrangement that only after the closure element is opened, the deliveryof the paste starts and thus piling up of the delivery medium andenhancement of the operating forces are avoided. FIG. 3 shows a simplerembodiment of the closure element communicating with the lever key. Onthis occasion a cover lock with plane surfaces is molded on the leverkey, the cover lock being tangentially movable in relation to the frontsurface of the discharge bore. Advantageously this embodiment isespecially simple in manufacture and assembly.

A further advantageous form of embodiment is disclosed in claim 18. Theadvantages, which can be attained in this embodiment, consist inparticular in that a dispenser, which can be manufactured with simplemeans, can be manually operated by finger pressure, and that measuresfor attaining a high suction effect permit the combination for examplewith commercial tubes serving as storage containers, whereby thematerial can be protected without an additional cap against drying-in,microbian attack and storage losses by an automatically controllableclosure, and that environmental pollution is reduced by reusing thedispenser, which can be separated from the storage container.

The advantages, which can be attained by the invention, consistespecially in that the delivery plunger is movable in a cylinder, whichis free of components, as e.g. a compression spring, and which is freeof non-usable spaces, which are produced for example in the embodimentof suction and pressure valve zones.

This permits a function of the delivery plunger without or only with aminimum dead space. This means that during an effected suction lift amaximum underpressure can be achieved, by means of which cream-like oreven viscous materials become capable of being sucked and thus capableof being pumped.

A further support of the suction behaviour is considered in that withthe movement start of the suction lift, the suction valve is openedmechanically and without delay not only by underpressure, but also by areleasable connection with the delivery plunger. By means of thisadhesive and binding forces on the suction valve seat are surmounted,and charging of the cylinder chamber and thus a safe function areensured.

It is expedient that the valve cone, located in the delivery plunger,when bearing on the valve seat, forms a reception with the deliveryplunger, which reception can be filled by an appendage of the suctionvalve. Consequently, side rooms which cannot be used for the suctionprocess are avoided.

It seems to be advantageous that the releasable connection between thedelivery plunger and the suction valve are formed by the reception andby an appendage, which preferably are directed towards each otherconically tapering. By the conical embodiment of the releasableconnection a positive locking between the suction valve and the deliveryplunger is produced in simple manner, which causes a definable drivingforce.

It is expedient that the releasable connection between the deliveryplunger and the suction valve can bear a lower axial force than theretaining force of the lift stops on the segments of the suction valve.It can be achieved by this that the snap engagement of the suction valvewith the resilient lift stops cannot be released.

It is also advantageous for ensuring the function that the releasableconnection between the delivery plunger and the suction valve bears alower axial force than the biasing force, associated with this positionof the delivery plunger, of the restoring spring. This ensures that thedelivery plunger or the metering head, respectively, can always moveback into its starting position.

A preferred embodiment of the delivery plunger and its attachment isgiven by the fact that the restoring spring takes its bearing on the oneside on a flange connected with the delivery plunger and on the otherside on the housing. By means of this it is achieved that the deliveryplunger together with its components can be manufactured as apreassembly group and for assembly it is merely to be placed into themetering head, as its attachment is performed via the restoring spring.

The embodiment of the delivery plunger as a preassembly group consistsin that a bush is fixedly connected with the delivery plunger and on theone hand serves for supporting the compression spring and on the otherhand takes its bearing in the bore.

An advantageous embodiment of the metering head is considered in thefact that a metering head comprises an axis located transversely to theaxis of the delivery plunger, which former axis has in common a controlplunger, a tappet and a valve cone. By means of this a space-saving,handling-oriented arrangement of the mouthpiece valve is achieved withsimple means.

It is expedient that the control plunger, the tappet and the valve conecan be manufactured in one piece and in a flexible material, and thatalso the biasing spring can be molded on the control plunger.

For the purpose of sealing the mouthpiece valve it is provided that inthe non-actuated position the prestressing force of the biasing springclamped between the control plunger and a cover has the valve cone bearon a valve seat. This arrangement proves to be especiallyhandling-oriented, as the mouthpiece valve is automatically opened whenproducing the delivery pressure. It is advantageous for the applicationthat no foreign materials can enter into the region within themouthpiece valve, as a valve opening is equivalent to a meteringquantity discharging under pressure.

Another embodiment of the control plunger consists in that the latter isformed as a pressure sealed, flexible disk, which can be swung out likea membrane about its clamping point. This results in a low-friction,i.e. easy responsive and reliably sealing arrangement. The disk can alsobe manufactured in one piece with the tappet and the valve seat.

A further advantageous embodiment of the control plunger is that thelatter can be designed as flexible, pressure sealed bellows, by theshaping of which the valve cone resiliently takes its bearing on thevalve seat.

A special embodiment of the external side of the mouthpiece is effectedin that the mouthpiece valve comprises a front surface, which passesover into a half shell or into a trough.

Examples of embodiment are described taken in conjunction with thedrawing, in which

FIG. 1 shows a side view with a closure, non-actuated,

FIG. 2 shows a side view with a closure, actuated,

FIG. 3 shows a side view of a lever key,

FIG. 4 shows a pressure valve in side view,

FIG. 5 shows an suction valve in plan view,

FIG. 6 shows a pressure valve in plan view,

FIG. 7 shows an suction valve in side view,

FIG. 8 shows a side view, without a closure, non-actuated,

FIG. 9 shows a side view, without a closure, actuated,

FIG. 10 shows a pressure valve with a friction bar,

FIG. 11 shows a pressure valve with a plug cone,

FIG. 12 shows a longitudinal section, non-actuated, of a furtherembodiment,

FIG. 13 shows a longitudinal section, actuated,

FIG. 14 shows a partial longitudinal section,

FIG. 15 shows a partial longitudinal section,

FIG. 16, shows a detail, stripper surface,

FIG. 17 shows a detail, stripper surface.

A guide housing 1 (FIGS. 1, 2) is rigidly connected with a deliverycylinder 3 via a flange 2. Both parts can also be manufactured in onepiece. At the lower end of the delivery cylinder 3 a front wall 4 islocated, which is flush with a plane surface 5 of an suction valve 6, onthe conical valve seat 7 of which guide segments 8 are adjoined, whichare provided with stop edges 9 for a lift stop. A thread 10 representsthe communication with a storage container 11, which is preferablyformed as a flexible tube.

In a delivery cylinder 3 a pump chamber 12 is located, on the inner wallof which a plunger 13 with its sealing 14 is slidable. The front sidesof the plunger 13, consisting of sealing 14, plane surface 16 of theclosed pressure valve 17 (FIG. 2), form a plane. On the pressure valve17 guide webs 18 and a spring bar 19 are molded on, which can belaterally swung out and which takes its bearing on a supporting surface20 of the metering head 21 and which keeps the pressure valve in aclosed position.

In the actuated position in FIG. 2, the plane surface 16 of the pressurevalve 17 contacts the plane surface 5 of the suction valve 6. Thiscontact surface between suction valve 26' and pressure valve 21 isillustrated in FIG. 11 as a contact zone b. On the conical seat 7 of thepressure valve 21 a plug cone 22 is adjoined, which has a small coneangle in the direction of the valve axis, in order to achieve areleasable clinging in a corresponding recess of the suction valve 26'.

FIG. 10 shows the contact zone c between the bore 25 of the suctionvalve 26 and a friction bar 24, which is fixedly connected with apressure valve 23. The contact zone c produces a sealing andfriction-generating sliding connection between the pressure valve 23 andthe suction valve 26, by means of which a mechanical control of thepressure and suction valves 23, 26 is attainable in dependance on themovement of the plunger 13.

According to FIGS. 8 and 9 the metering head 27 comprises in its simpleform of embodiment a discharge bore 28, which can be closed by a cap 29.On the metering head 27 a cylindrical sliding guidance 30 is molded on,which is supposed to prevent tilting during actuation by its length. Thecircumferential edge 31 with the stop 32 forms the upper lift stop. Onthe guide housing 1 axial slits 33 are provided for radial expansion forthe purpose of assembling the sliding guidance 30.

On its upper end the plunger 13 comprises a flange 34, which sealinglyabuts on a corresponding plane surface of the metering head 27, due tothe restoring spring 35, which is clamped between the shoulder 36 andthe flange 34.

In a further improvement the metering head 37 contains a mouthpiece 38according to FIGS. 1 and 2, on the valve seat 39 of which a closureelement 40 abuts while being actuated by a compression spring 41. Theclosure element 40 is formed as a valve cone and is connected with ashaft 42, which is extended through the bore 43 out of the metering head37, whereby a sealing ring 44 takes its bearing. The lever key 45 ispivotably supported in a fulcrum 46 and takes its bearing on a collar47, as soon as the lever key 45 is loaded. The collar 47 can be designedas a retaining ring.

The actuation-force component produced by finger pressure on the leverkey 45, which component lies in the axis of the plunger 13 and isnecessary for moving the closure element 40, is smaller than the force,which is to be applied for moving the plunger 13, which force can bedetermined by the length of the lever, prestressing of the compressionspring 41 and the restoring spring 35.

In FIG. 3 a lever key 50 is shown, which snap-engages on cams 51 andwhich is connected with a closure element 52, which is pivotable aboutthe fulcrum 46. The closure element 52 is formed as a cover lock. Thenose 53 connected with the lever key 50 abuts on the metering head 27while being actuated by the compression spring and produces a sealingforce on the closure element 52.

Functional description according to FIGS. 8, 9, 10, 11.

On the tube 11 filled with a paste the paste dispenser consisting of theremaining parts is screwed onto the thread 10. At first the air betweenthe suction valve 5 and the tube 11 is to be removed by repeated fingerpressure on the metering head 27. The effective performance of thismeasure is decisive for the further function and characterizes theadvantageous embodiment of the invention. The very small dead spaceresulting with a pressed-down position of the metering head 27 in thecontact zone a in FIG. 9, results in an effective underpressure, whenthe plunger 13 is returned into the non-actuated position, whichunderpressure is generated by the sealing 14 and by the pressure valve17, which abuts in a sealing and resilient manner. The opening of thesuction valve 6 immediately effected with the beginning of the suctionlift while being cooperated by the adhesion in the contact zone a, leadsto suction of the air in the region of the thread 10. When the deliverylift is repeated, the suction valve closes in known manner and thepressure valve 17, resiliently abutting by the spring bar 19, opens.

According to FIG. 11 for the purpose of opening the suction valve use ismade of a positive locking in lieu of the adhesive force. The plug cone22 as a continuation of the valve seat 21' of the pressure valve 21 ismounted in a corresponding recess in the suction valve 26'. With thesuction movement of the plunger 13 the suction valve 26' is driven asfar as to its stop edge 9. Then the positive locking in the contact zoneb is released.

In FIG. 10 in the contact zone c an additional sealing force is appliedby frictional locking at the bore 25 of the suction valve 26, as long asthe pressure valve 23 with the plunger is in the delivery lift.Simultaneously, the friction in the contact zone c acts as an additionalopening force onto the pressure valve 23, the opening path of which islimited by the spring bar 19 abutting on the supporting surface 20. Inthis case the spring bar 19 is slightly shortened, it acts only as astop limit without spring action.

In the suction lift the frictional forces produced in the contact zone cact in the reversed direction. The suction valve 26 is additionallyelevated, while the pressure valve 23 is additionally pressed into theclosing position. It is advantageous that the aforesaid influence ontothe control movement of pressure and suction valve can be effected inany desirable lift position or lift reversal.

FIGS. 1 and 2 show an embodiment, which provides a closure on themouthpiece 38 for media, which are particularly liable to dry in or toemit gas. When actuating the lever key 45, the closure element 40 iselevated from its valve seat 39 by surmounting the prestressing force ofthe compression spring 41, by the lever key 45 tractively moving theshaft 42 by abutting on the collar 47. When the lever key 45 contactsthe stopper 48, the closing element 40 reaches its maximum openposition. In case of further increasement of the actuating force on thelever key 45 the metering head 37 with its sliding guidance 30 is moveddownward in the guide housing 1. It is advantageous with this embodimentthat only after a maximal opening of the mouthpiece 38 the delivery liftof the plunger 13 can be triggered, by means of which an easy-runningactuation is achieved.

The extra long sliding guidance 30 together with the guide of theplunger 13 in the delivery cylinder 3 prevents tilting. In addition tothe arrangement of the valves the restoring spring 35 located outside ofthe pump chamber 12 contributes to the fact that the dead space in thestop position of the plunger 13 can be kept very small.

The restoring spring 35 causes a sealing abutment of the flange 34,connected with the plunger 13, on the metering head 37. The openingposition of the pressure valve 17 shown in FIG. 1 takes place in thedelivery phase, the spring bar 19 molded on the pressure valve 17swinging out. The spring bar 19 is guided around the shaft 42 in theregion of the latter and eccentrically bears on the supporting surface20.

In the example of embodiment according to FIGS. 12 and 13, which is alsoapplicable for liquids, a housing 101 is connected in one piece with acylinder 200. A thread 101' represents the releasable connection with astorage chamber 102', the storage container of which is not particularlyshown. An suction valve 103 in its closed stage (FIG. 13) with its platesurface 104 is flush with a cylinder bottom 105, while a conicalappendage 106 adjoining the plate surface 104 projects into a cylinderchamber 107 and releasably clings in a conical reception 109 in thelower stop position of a delivery plunger 108 (FIG. 13). The suctionvalve 103 is guided in a bore 110 by means of segments 111 and is fixedby lift stops 112 in its open position. In this position of the deliveryplunger 108 the cylinder chamber 107 comprises a volume of about zero.In the delivery plunger 108 a longitudinally movable valve cone 113 islocated, which sealingly takes its bearing on a valve seat 115 by acompression spring 114 (FIG. 12).

On its other side the compression spring 114 supports on a bush 116,which is fixedly connected with the delivery plunger 108 and which issealingly mounted in a bore 117. The bore 117 produces the connectionwith a bore 124'. A flange 118 is molded onto the delivery plunger 108and serves for supporting a restoring spring 119, which iscounter-supported in the housing 1. The restoring spring 119simultaneously serves as a longitudinal fixing of the delivery plunger108 in the metering head 120. The latter is connected with a guidecylinder 121, the stop 122 of which takes its bearing on knobs 123 inthe non-actuated position. The knobs 123 are engraved into the frontside of the housing 101 after assembly. In the metering head 120 a bore124 is located for receiving and sealing a slidable control plunger 125,which is connected with a tappet 126 and on the end of which a valvecone 127 is located, which comprises longitudinally oriented supplychannels 127'.

By means of a biasing spring 129 the valve cone 127 takes its bearing ona valve seat 128, the surfaces of which are directed inwardly towardsthe bore 124'. The valve cone 127 and the valve seat 128 form amouthpiece valve 128'.

The biasing spring 129 is supported on the one side on the controlplunger 125 and on the other side on a cover 130, which is fixedlyconnected with the metering head 120 and which comprises an air bore131. In FIG. 14 the control plunger is replaced by a flexible disk 132,which is sealingly fixed at a clamping point 133 and which can be swungabout the latter towards both sides. In FIG. 15 the control plunger isreplaced by flexible bellows 135, by the shaping of which an axialspring biasing can be attained, which has the valve cone 128 bear on thevalve seat 128. By this manner the biasing spring 129 can be saved.

FIG. 15 shows a special embodiment of the stripper surface 136 of themouthpiece valve 128'. In this case the stripper surface 136 is flushwith a front surface 136', which represents a cylinder section throughthe metering head 120 and which passes over into a half shell 137. InFIG. 17 the half shell 137 is replaced by a trough 137'. Botharrangements prevent draining or dropping off of excess cream.

When actuating the metering head 120 for the first time, the latter ismoved from the starting position (FIG. 12) into the lower stop position(FIG. 13). During this process the pressure valve 113 is opened by thecompression pressure produced in the cylinder chamber 107, and thesuction valve 103 is closed. As soon as the delivery plunger 108approaches the cylinder bottom 105, the appendage 106 of the suctionvalve 103 engages with the reception 109 of the delivery plunger 108 andproduces a releasable connection at this place. At the lower dead pointthe delivery plunger 108 forms a cylinder chamber 107, which correspondsto an approximate zero volume. When the metering head 120 is returnedinto the starting position (FIG. 12), the suction valve 103 ismechanically driven with the delivery plunger 108, until the lift stops112 of the suction valve 103 rest on the housing 101. The opening of thesuction valve 103 is also supported by the underpressure produced.

When again exerting the pressure lift onto the metering head 120, thevalve cone 113 opens with a simultaneous closure of the suction valve103, and a delivery pressure is produced in the bore 124 and 124'. Thispressure also actuates upon the control plunger 125, the effective worksurface of which is diminished by the surfaces, projected normal to thelongitudinal axis, of the valve cone 127. As soon as the force ofpressure, acting onto the control plunger 125, of the delivery mediumexceeds the prestressing force of the biasing spring 129, the controlplunger 125 moves opposite the operation of the biasing spring 129. Onthis occasion the valve cone 127 is elevated from the valve seat 128 anddischarges outwards a partial amount of paste.

Air locks in the storage chamber 102' are sucked off by the aforesaidsuction conditions, without the function being permanently interrupted.

I claim:
 1. A finger actuatable dispenser for the metered discharge ofliquids and pasty masses from a container comprising:connecting means toconnect said dispenser to said container, a dispenser housing, adelivery pump connected to said housing and axially movable within saidhousing, said delivery pump having a discharge bore, a pump chamber(12), a pressure valve (17) to open and close one end said pump chamber,a plunger (13), a seal (14) connected to one end of said plunger, asuction valve (6) connected to the other end of said pump chamber toopen and close another end of said pump chamber, said suction valve (6)and pressure valve (17) being axially spaced from each other, saidsuction valve having means for limiting axial movement within saidpressure chamber, open and close means (40, 52) in said dispenser toopen and close said discharge bore, a restoring spring (35) connected tosaid plunger and supported on a shoulder within said dispenser to urgesaid plunger to a non-delivery position, said delivery pump having astop (31) on its outer surface to cooperate with a dispenser housingstop (32) to limit the relative axial movement of said delivery pump andsaid plunger, said pressure valve contacting said suction valve toreduce said pump chamber to a minimum volume, said pressure valvecooperating with said seal to close said pump chamber one end when theplunger is moved to increase the volume of said pump chamber.
 2. Adispenser according to claim 1 wherein a contact zone (a) is formed in alower plunger position by plane surfaces (5, 16) of the pressure valveand the suction valve to produce adhesive forces with the aid of adelivery medium.
 3. A dispenser according to claim 2 wherein the suctionvalve (6) is longitudinally movable with the plunger (13) in a suctiondirection by an under pressure and by adhesive forces.
 4. A dispenseraccording to claim 1 wherein the pressure valve (21) has a valve seat(21') connected to the plunger and a plug cone (22), and said,plug conecorresponds a corresponding conical bore in the suction valve (26'). 5.A dispenser according to claim 1 wherein a friction bar (24) is fixedlyconnected to the pressure valve (23), said friction bar extends towardsaid suction valve and penetrates a bore (25) in the suction valve (26)and has a contact zone (c) with said suction valve.
 6. A dispenseraccording to claim 5 wherein the friction bar is positioned and sized toprovide with the downward movement of the plunger (13) additionalopening forces on the contact zone (c) on the suction valve (26), andadditional closing forces on the pressure valve (23).
 7. A dispenseraccording to claim 5 wherein the friction bar is positioned and sized toprovide with the upward movement of the plunger (13) additional openingforces on the contact zone (c) on the suction valve (26), and additionalclosing forces on the pressure valve (26).
 8. A dispenser according toclaim 1 wherein the suction valve (6, 26, 26') has a valve plate with aconical valve seat (7), and guide segments (8) having said means forlimiting which comprises stop edges (9), said guide segments and stopedges being molded on said conical valve seat.
 9. A dispenser accordingto claim 1 wherein the pressure valve (17, 21, 23) has a valve platewith the conical valve seat (7), on which guide webs (18) and a springbar (19) are molded.
 10. A dispenser according to claim 1 wherein alever key (45) is connected to said open and close means, said lever keyis pivotable about a fulcrum (46) to a metering head (37) which formsthe discharge bore.
 11. A dispenser according to claim 10 wherein theactuating force, to move the lever key (45) on the metering head (37),is smaller than the force which is required for the movement of themetering head (37).
 12. A dispenser according to claim 10 wherein theopen and close means has a shaft (42) that passes through said meteringhead and is connected to said lever key, said shaft being sealableagainst a metering head bore (43) by means of an O-ring (44).
 13. Adispenser according to claim 12, wherein the shaft (42) has a collar(47) formed as a retaining ring to connect said lever key to said shaft.14. A dispenser according to claim 1 wherein a lever key (50) isconnected with said open and close means (52), said open and close meansis formed as a cover lock and is movable tangentially to a from surfaceof the discharge bore (28).
 15. A dispenser according to claim 14wherein a nose (53) is connected to the lever key (50) and is supportedon a metering head (27) in a non-actuated position, and wherein sealingpressure of the open and close means on front surfaces of the dischargebore (28) is intensified.
 16. A dispenser according to claim 1 whereinthe plunger (13) has a molded-on flange (34) and is manufactured of aflexible plastic material.
 17. A dispenser according to claim 1 whereinin the non-actuated position, the depth of a guide on the delivery pumpin the dispenser housing (1) is greater than the depth of penetration ofthe plunger (13) into a delivery cylinder (3) which defines said pumpchamber.
 18. A dispenser according to claim 1, wherein the pump chamberdefines a cylinder, the volume of which is zero when the plunger is onthe cylinder bottom, and in that in this position there is a releasableconnection between the plunger and the suction valve, the open and closemeans comprising a valve cone which bears against a valve seat (128) ofthe discharge bore, and a control means (125) connected to said valvecone for controlling its movement, said control means includes a biasingmeans (129) and being reciprocally longitudinally movable by deliverypressure from the pump and by said biasing means (129).
 19. A dispenseraccording to claim 18, wherein said plunger is slidable within saidcylinder, the plunger has a bottom plunger valve seat (115) to receivesaid pressure valve which is axially movable within the plunger (108),said valve seat forming a reception (109) which can be fried by anappendage (106) extending from the suction valve (103).
 20. A dispenseraccording to claim 18, wherein the releasable connection between theplunger (108) and the suction valve (103) is formed by a receptiongroove in a plunger valve seat and an appendage (106) extending from thesuction valve.
 21. A dispenser according to claim 20, wherein thesuction valve has a guide (111) having said means for limiting thereonto limit the movement of the suction valve, the releasable connectionbetween the plunger (108) and the suction valve (103) having a loweraxial force than a retaining force of the means for limiting on theguide (111) of the suction valve (103).
 22. A dispenser according toclaim 20, wherein the releasable connection between the delivery plunger(108) and the suction valve (103) having a lower axial force than abiasing force, associated with the restoring spring (119).
 23. Adispenser according to claim 18, wherein said restoring spring (119)bears on a flange (118) connected to the plunger (108) and bears on saidshoulder.
 24. A dispenser according to claim 18, wherein a bushing (116)is fixedly connected to the plunger (108) and supports a pressure spring(114) and is positioned in a plunger bore (117).
 25. A dispenseraccording to claim 18, wherein the discharge bore is formed by ametering head (120) which comprises an axis located transversely to theaxis of the plunger (108), said metering head having said control means(125), said valve cone (127) and an interconnecting tappet (126)disposed therein.
 26. A dispenser according to claim 25, wherein thecontrol means (125), the tappet (126) and the valve cone (127) areone-piece and are made from a flexible material.
 27. A dispenseraccording to claim 26, wherein the control means has said biasing meansmolded thereon.
 28. A dispenser according to claim 18, wherein in thenon-actuated position the force of said biasing means (129) is clampedbetween the control means (125) and a cover (130) and the valve cone(127) bears on the valve seat (128).
 29. A dispenser according to claim18, wherein the control means is a pressure scaled, flexible disk (132),which can be swung out about a point at which it is clamped to thedispenser.
 30. A dispenser according to claim 18, wherein biasing meansof the control means is a flexible pressure sealed bellows (135), saidsealed bellows urges the valve cone (127) resiliently on the valve seat(128).
 31. A dispenser according to claim 18, wherein the valve cone isa mouth-piece valve (128') having a from surface (136), disposed over ahalf shell (137) or a trough (137') of a metering head of the dispenserof a metering head of the dispenser.